arm64: defconfig: re-enable Qualcomm DB410c USB

Stephen Boyd reworked some Qualcomm USB code earlier this year.
The result requires a few different config options to be enabled
in order for the USB on the DragonBoard 410c to continue working,
but these were never added to arm64 "defconfig".  As a result, USB
on that board stopped working during the v4.13-rc1 merge window.

Re-enable this functionality by setting the needed config options
in the arm64 "defconfig" file.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>